Three-dimensional image processing apparatus, optical axis adjusting method, and optical axis adjustment supporting method

Abstract

The present invention provides a technique for enabling even a person having no expert knowledge to adjust the direction of an optical axis easily with high precision. In a three-dimensional image processing apparatus having plural image capturing apparatuses, optical center of an image from an image capturing apparatus is stored for each of the image capturing apparatuses. A mark indicative of the optical center is superimposed on an image obtained from the image capturing apparatus. By referring to the mark for each of the image capturing apparatuses, the orientation of each of the image capturing apparatuses is adjusted so that all of the marks overlay on the same point on an object.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a three-dimensional image processing apparatus for obtaining three-dimensional information of an object from stereoscopic images captured by plural image capturing apparatuses and, more particularly, to a technique for adjusting directions of optical axes of the image capturing apparatuses. [0003] 2. Description of the Related Art [0004] One of the methods of obtaining three-dimensional information of an object from images is a method of capturing images of a predetermined image capture area by plural image capturing apparatuses disposed at predetermined intervals and obtaining corresponding relations of image formation points of the object on the captured plural images among the image capturing apparatuses. This method is generally called a stereo image process. [0005] In a three-dimensional image processing apparatus using the stereo image process, the optical axes of image capturi...

AI Technical Summary

Benefits of technology

[0009] The present invention has been achieved in view of the circumstances and an object of the invention is to provide a technique for enabling even a person having no expert knowledge to adjust the direction of an optical axis easily with high precision.

[0012] The “optical center of an image” corresponds to the meeting point of an optical axis and an image pickup device of the image capturing apparatus, and the “mark indicative of optical center” corresponds to a mark obtained by visualizing information corresponding to the optical axis or a fixation point on the optical axis. Consequently, the user can visually grasp the direction of the image capturing apparatus by seeing an image displayed on the display. Thus, even if the “optical center of an image” and the “center of the image” do not match each other, by referring to marks of the image capturing apparatuses, the directions of the optical axes can be adjusted with high precision, and crossing of the optical axes can be realized relatively easily. For example, in the case of performing adjustment manually, it is sufficient to adjust the orientations of the image capturing apparatuses so that all of marks overlay the same point on an object by seeing the marks of the image capturing apparatuses. Obviously, the processor can automatically adjust the orientation of the image capturing apparatuses on the basis of the marks.

[0013] When the image capturing apparatus has plural focal distances, it is preferable to store optical center of an image at each of the focal distances in the storage. When the focal distance changes, there is the possibility that the position of the optical center of the image changes. By properly switching information read from the storage in accordance with the focal distance of the image capturing apparatus, a mark can be displayed always in a proper position. Therefore, precision of the optical axis adjustment can be improved.

[0014] It is also preferable that the display enlargedly displays a part including the mark. By seeing an enlarged image, fine adjustment and matching of the direction of the optical axis can be performed with high precision.

[0022] Thus, according to the present invention, even a person having no expert knowledge can adjust the directions of optical axes easily and with high precision.

Problems solved by technology

Although “crossing” has various advantages as described above, in reality, the optical axes are not seen, so that it is very difficult to adjust the directions of the optical axes of image capturing apparatuses.

It is all the more difficult for the user having no expert knowledge of image processing.

In the actual image capturing apparatus, however, there is no guarantee that the optical axis passes the center of the image pickup device due to mount variations of the image pickup device and an optical system (refer to FIG. 13).

Moreover, there is also the possibility that a deviation amount between the passing point of the optical axis in the image pickup device (the optical center of the image) and the center of the image pickup device (the center of the image) changes when the focal distance changes.

In the case where a center portion of an image does not include a characteristic image point and in the case where a similar pattern repeatedly appears in an image, erroneous correspondence between images may occur.

Therefore, the precision of optical axis adjustment in the conventional technique is limited.

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